DE102022003953B3 - Method of operating a vehicle - Google Patents

Abstract

The invention relates to a method for operating a vehicle (1), in which a steering wheel is positioned in a safety position when an automated driving operation is activated and in a steering position when a driving task is transferred from the vehicle (1) to a driver of the vehicle (1). According to the invention, in automated driving mode, a route (F) ahead of the vehicle (1) is analyzed with regard to the suitability of handing over the driving task, - the route (F) is analyzed in such a way that an amount of a maximum steering angle with regard to the route (F) divided into segments and a driving speed at which the vehicle (1) travels on the respective segment are predicted, and based on the predicted steering angle and the predicted driving speed for each of the segments, a degree of suitability for handing over the driving task the driver of the vehicle (1) is determined.

Description

The invention relates to a method for operating a vehicle, in which a steering wheel is positioned in a safety position when an automated driving operation is activated and in a steering position when a driving task is handed over from the vehicle to a driver of the vehicle.

From the EP 2 915 718 A1 a device and a method for continuously setting a limit for autonomous drive availability and a motor vehicle with such a device are known. The vehicle has autonomous driving capability and sensors to collect vehicle surroundings information and vehicle dynamics sensors. Furthermore, the vehicle includes at least one positioning arrangement that provides map data with associated information; a route planning device that enables route planning, a vehicle driver monitoring arrangement that provides driver monitoring information; and a real-time information capture arrangement that captures traffic information and/or weather information. The autonomous drive availability limit is calculated based on a planned route and at least one of vehicle environmental information, vehicle dynamics parameters, driver monitoring information, map data, traffic information and weather information. Changes to the calculated limit for the planned route are output via a human-machine interface located in the vehicle.

In addition, the describes DE 10 2021 002 297 B3 a vehicle with a steering wheel arrangement. The steering wheel arrangement comprises a control unit and a steering wheel which is arranged on a steering column and is connected to the control unit and can be positioned from a steering position to a safety position. Furthermore, the steering wheel arrangement comprises an adjustment unit connected to the control unit for positioning the steering wheel arranged on the steering column from the steering position to the safety position. In addition, the steering wheel arrangement is designed to vibrate when positioned from the steering position to the safety position.

From the DE 10 2014 225 680 A1 a method for handing over a driving task to a driver of a vehicle is known, in which it is provided that the duration of a handover phase is adapted to a state of attention of the driver, with additional environmental conditions being able to be taken into account during the adaptation.

From the DE 10 2018 207 675 A1 a method for switching the operation of a vehicle between different automation levels is known, in which a switchover from a current automation level to a lower automation level occurs when a system limit of the current automation level is reached.

From the DE 10 2010 042 048 A1 is a method for supporting a driver of a vehicle during an automated driving maneuver, it being provided that vehicle control can be handed over to the driver if the driver intervenes in a steering or presses an accelerator pedal during the driving maneuver.

From the DE 10 2013 110 852 A1 a method for highly automated or autonomous operation of a vehicle on certain road sections is known, whereby the driver is shown a distance to the beginning of a road section on which highly automated or autonomous operation is possible.

From the DE 10 2020 129 887 A1 a method for switching the operation of a vehicle between different levels of automation is known, wherein a vehicle interior function is changed during the switching.

The invention is based on the object of specifying a method for operating a vehicle.

The object is achieved according to the invention by a method which has the features specified in claim 1.

Advantageous embodiments of the invention are the subject of the subclaims.

A method for operating a vehicle provides that a steering wheel is positioned in a safety position when an automated driving operation is activated and in a steering position when a driving task is handed over from the vehicle to a driver of the vehicle. According to the invention, in automated driving mode, a route ahead of the vehicle is analyzed with regard to the suitability of handing over the driving task. The analysis of the route is carried out in such a way that an amount of a maximum steering angle with regard to the route divided into segments and a driving speed at which the vehicle travels on the respective segment are predicted, and based on the predicted steering angle and the predicted driving speed for each of the segments a degree of suitability for handing over the driving task to the Driver of the vehicle identified. The determined different degrees of suitability for each segment of the route are displayed to the driver on a display unit on the vehicle.

By using the method, a stressful situation for the driver of the vehicle with regard to taking over the driving task can be largely avoided, since the method is used to determine a suitable location for handing over the driving task and gripping the steering wheel, especially with a square shape, is simplified. The degree of suitability is particularly comparatively high when the vehicle is on a straight route and therefore a steering movement does not have to be carried out immediately when the steering wheel is positioned in the steering position and the driver takes over the driving task.

The method therefore takes into account that the vehicle is not, for example, in a comparatively tight curve when the driving task is handed over to the driver of the vehicle, since the level of difficulty for handover when driving in a tight curve can be relatively high and more accident-prone.

In one embodiment, the different suitability levels are displayed in different colors on the display unit. Using the different colors, for example red, yellow, green, the suitability levels can be visualized and the driver can assess based on the color whether it is currently critical or non-critical to take on the driving task in order to move the vehicle in manual driving mode.

In a further embodiment it is provided that the driver of the vehicle requests the positioning of the steering wheel in the steering position by actuating an actuating element if he has the appropriate level of suitability and intends to take on the driving task. The driver can therefore use the suitability levels displayed in color to determine a time at which the steering wheel is positioned from the safety position to the steering position, so that the driver can carry out the driving task in manual driving mode of the vehicle.

If the vehicle recognizes the need to hand over the driving task to the driver and the vehicle is currently cornering, a further development of the method checks whether the handover is possible at a later point in time on a segment of the route with a higher degree of suitability. The check determines a point in relation to a currently or subsequently traveled segment of the route at which the handover of the driving task can take place essentially safely without the vehicle endangering itself and other road users, for example when cornering.

In a possible further development, if it is determined during the check that the handover should take place at a later time, when the driving task is handed over at a later time on the segment with a higher degree of suitability, the steering wheel is automatically positioned in the steering position at a later time. Thus, in addition to the display, the driver of the vehicle can be made aware that he is taking over the driving task in relation to the vehicle and that the vehicle is being moved further in manual driving mode.

In a further possible embodiment of the method, a suitability level suitable for handing over the driving task is displayed in color if the segment has a straight route and a wheel angle is 2° or less for a driving time of at least 3 seconds. This makes it possible to ensure as far as possible that the driver's takeover of the driving task is stress-free and free of complications, without posing a potential danger to road users in the area surrounding the vehicle.

Furthermore, in one embodiment, the method provides that a curve radius of the route divided into segments and traffic information applicable to the route are continuously recorded. Based on the respective curve radius, the locations are then determined whose degree of suitability for handing over the driving task is comparatively high and the handover can take place essentially stress-free for the driver.

In one embodiment of the method, a countdown, i.e. a countdown, until the later point in time is reached and the driving task is handed over to the driver at this later point in time is optically output by means of a progress display shown on the display unit. The driver recognizes from the display that the handover is imminent and that the vehicle is then on a segment with a straight route, so that the handover can take place essentially without complications.

In particular, the traffic information is recorded continuously in order to determine critical traffic situations in which the driver of the vehicle should move it manually, for example at the scene of an accident on one of the segments of the road ahead of the vehicle cke, which is reached comparatively quickly by the vehicle.

Exemplary embodiments of the invention are explained in more detail below with reference to drawings.

• 1 schematisch eine Fahrstrecke mit einer markierten aktuellen Position und einer markierten Übergabeendposition,
• 2 schematisch eine Fahrstrecke mit einer Kurve und einem in der Kurve im autonomen Fahrbetrieb fahrenden Fahrzeug,
• 3 schematisch eine Fahrstrecke mit einer Kurve, ein autonom auf die Kurve zufahrendes Fahrzeug und mehrere Fortschrittsanzeigen und
• 4 schematisch zeitabhängige Fortschrittsanzeigen zur bevorstehenden Übergabe einer Fahraufgabe.

Show:

• 1 schematically a route with a marked current position and a marked transfer end position,
• 2 schematically a route with a curve and a vehicle driving autonomously in the curve,
• 3 schematically a route with a curve, a vehicle driving autonomously towards the curve and several progress displays and
• 4 Schematic time-dependent progress displays for the impending handover of a driving task.

Corresponding parts are provided with the same reference numbers in all figures.

1 shows a route F with a straight route, with a current position P _a and a handover end position P _e on the route F for handing over a driving task of a vehicle 1 driving in automated, in particular in autonomous driving mode, which in 2 and 3 is shown in more detail.

In autonomous driving operation, a driving task in relation to the vehicle 1 is carried out entirely by the vehicle 1, so that a driver of the vehicle 1 can pursue other activities, such as processing emails, reading, resting, etc., during autonomous driving operation.

The vehicle 1 has so-called steer-by-wire steering, since a steering wheel, which can also have an angular shape, is not required in autonomous driving and is therefore positioned from a steering position to a safety position, which gives the driver greater freedom can be made available. When the steering wheel is positioned in the safety position, a driver's seat can be used in a variety of ways, for example a reclining position of a driver's seat can be adjusted.

Even at level 4 in relation to autonomous driving, a driving situation can occur in which the driving task is handed back to the driver within a predetermined, so-called drop interval, for example 30 seconds. Such a driving situation can occur due to failed sensors, for example due to icing, or for safety reasons, for example when passing through a construction site with several or even missing road markings, which can result in the vehicle 1 losing its orientation. The driver can also take over the driving task as required by the vehicle as a termination of the autonomous driving operation, for example due to weather events, an accident, a narrowing of the road, a fault report, etc.

In such a driving situation, the vehicle 1 continues to drive from the current position P _a for a predetermined period of time of, for example, 30 seconds to the handover end position P _e in automated driving mode, so that the driver can move from the current position P _a of the vehicle 1 to the handover end position P _e sufficient time is available to take over the driving task of manual driving of the vehicle 1.

The steering wheel is positioned from the safety position to the steering position regardless of the current curve position of the route F on which the vehicle 1 is traveling. When positioning the steering wheel in the steering position, it can collide with the driver's legs, especially if the steering wheel is angular. In particular, there is such a risk of collision at comparatively high steering angles, since the square steering wheel is turned into the steering position when positioning and protrudes downwards to the maximum.

In other words, taking on the driving task in a curve situation can be comparatively stressful for the driver of the vehicle 1, since on the one hand the driver has to observe traffic and, on the other hand, has to grasp the steering wheel as it moves out in a position in which the driver intuitively has a feeling for one has the set steering angle. This can be problematic when cornering, as the steering wheel is then presented to the driver in a position that is rotated compared to a rest position or zero position. Typically, a steering wheel angle is larger than a wheel angle, i.e. a steering angle, of steered vehicle wheels.

In addition, driving tests have shown that handing over the driving task to the driver of the vehicle 1 in curves leads to a maximum load, that is to say to a stressful situation, and the vehicle 1 has to be taken over safely again.

To allow the driver to take over the driving task to carry out manual driving and to simplify gripping the steering wheel, a method is described below.

The method provides that the route F ahead of the vehicle 1 is analyzed based on a steering angle to be set on the route F with regard to its suitability for handing over the driving task to the driver of the vehicle 1. This analysis is carried out, for example, up to a predetermined forecast horizon or up to a limit of a route F released for autonomous driving. In particular, the steering angle to be set is predicted based on a respective curve radius r of curves located on the route F, with a calculation of the steering angle being carried out on the basis of an algorithm stored for the autonomously driving vehicle 1.

The driver is shown a result of the analysis on a display unit in the vehicle 1, so that the driver can request that the driving task be handed over to the most suitable location.

In addition, the method provides that in the event of a need recognized by the vehicle to hand over the driving task from the vehicle 1 to the driver, for example due to a driving situation mentioned above, it is checked whether, if it is a curved section of the route, the handover takes place on a more suitable section of the route can take place and will be initiated at a later date.

In particular, the route F to be analyzed is divided into segments, which can, for example, be of the same length. For each of the segments, an amount of a maximum steering wheel angle is predicted, which is to be set in the respective segment. In addition, a driving speed at which the vehicle 1 is expected to travel in the respective segment is predicted for each segment.

Based on the predicted steering wheel angle and the predicted driving speed, a suitability level is calculated for each of the segments, which represents a measure of how suitable the respective segment is for handing over the driving task to the driver of the vehicle 1.

The driver of the vehicle 1 is shown the different suitability levels of the route F ahead on a vehicle-side display unit, the suitability levels being displayed using different colors assigned to them. The driver of the vehicle 1 is thus offered the opportunity to select a segment with a high degree of suitability for taking on the driving task if he wishes to take over the driving task. If the driver wishes to hand over the driving task, he activates an actuating element so that the steering wheel is positioned at a suitable point from the safety position to the steering position.

According to 2 the vehicle 1 is in a curve on the route F, whereby the driver, for example, wishes to take over the driving task. At a current position P _a in the segment, i.e. in particular the curve, a steering wheel angle, i.e. a wheel angle, is more than 2°, so that a degree of suitability for handing over the driving task is comparatively low and, if necessary, a warning message W is issued, with which of handing over the driving task is not recommended. For example, the route F ahead of the vehicle 1 can be displayed on the display unit, with the current position P _a or the segment on which the vehicle 1 is currently traveling being shown in red.

At a position P _g determined with respect to the route F, from which a straight route of the route F begins, a steering angle is less than 2°, so that from this position P _g a degree of suitability for handing over the driving task is high and the driver is given the means is displayed in a corresponding display. Here the segment can be displayed in green.

3 shows a route F with a curve into which the autonomously driving vehicle 1 enters, with the vehicle being requested to end the autonomous driving operation based on recorded traffic information, for example due to weather conditions, an accident, a narrowing of the road, another fault message, etc.

A current position P _a of the vehicle 1 is at the start of the curve, so that the degree of suitability for handing over the driving task is low and a warning message W is issued in the vehicle 1 in this regard.

In addition, it is checked whether there is a location with a high degree of suitability for handing over the driving task before an event E is reached, which requires the termination of the autonomous driving operation, so that this is initiated at a later point in time.

Using a progress display A, which shows progress until reaching the point with the high level of suitability, the driver of the vehicle 1 can see when the level of suitability is so high that the driving task can be handed over.

For example, when entering the curve, the progress display A shows a low level of suitability based on a green bar B2 that is small compared to a yellow bar B1. In the middle of the curve, the two bars B1, B2 are essentially the same length, so that the degree of suitability is still relatively low and at the position P _g , where the straight route begins, the progress indicator A shows a comparatively long green bar B2 as a high level of suitability for handing over the driving task to the driver.

The progress display A therefore displays a countdown to the beginning of a segment in which the degree of suitability for handover is comparatively high.

In particular, a segment of the route F that is suitable for handing over the driving task is determined if it has a comparatively straight route for a predetermined period of time of at least 3 seconds for the predicted driving speed and the steering angle is less than 2° or the steering wheel angle is less than 10° .

4 shows an example of the various progress displays A with a time reference, with the warning message W being issued at a time t ₀ and the degree of suitability for handing over the driving task is zero. Using the progress indicator A, only a yellow bar B1 is displayed.

Between the time t ₀ and a time t _0.5 , the degree of suitability is comparatively low, as in 3 is shown when the vehicle 1 moves towards a center of the curve. The green bar B2 is almost negligible compared to the yellow bar B1.

In the middle of the curve, at time t _0.5 , the two bars B1, B2 of the progress display A are of the same length and at the end of the curve, at time t _0.5 , the yellow bar B1 is small, so that the handover of the Driving task is imminent.

At a time t _u, the degree of suitability for handing over the driving task is very high and the progress display A only shows the green bar B2, which extends over the progress display A.

In particular, before each intended handover of the driving task to the driver of the vehicle 1, a so-called cross-check with road data is carried out, with a predictive route analysis being carried out with regard to straight and curved routes for a route profile within a handover interval.

The transfer of the driving task, i.e. the positioning of the steering wheel from the safety position to the steering position, is only triggered if the route is straight and the steering angle is less than 2° for at least 3 seconds remaining driving time. As described above, the route is straight if the steering angle is less than 2° and the steering wheel angle is less than 10°.

The driving speed of the vehicle 1 is predicted in particular for calculating the remaining travel time on a segment with a straight route.

By means of the method described above, it is possible to reduce the risk of accidents and a stressful situation for the driver of the vehicle 1 by handing over the driving task to the driver in the most suitable driving situation possible. This suitable driving situation is determined based on the course of the route F ahead of the vehicle 1 and a set steering angle resulting from the course of the route in conjunction with an expected driving speed. With regard to the expected driving speed that the vehicle 1 travels on a segment of the route F, it is determined whether it is a motorway, a residential street, etc. In addition, traffic information, i.e. traffic reports for the route F ahead, is taken into account, so that, for example, the vehicle 1 has a traffic jam report on one of the segments.

For example, if the vehicle 1 is driving on a highway at a comparatively high speed in a curve and there is a speed limit for an adjacent segment with a straight route, it is prioritized that the driving task is handed over at a later point in time, in particular when the vehicle 1 is on the segment with the straight route. The driving task is handed over if it can be reproduced, i.e. carried out, within a time range of legal requirements, in particular 3 seconds.

By means of the progress display A according to the determined degree of suitability of a position of the vehicle 1 on the route F ahead of it, the driver of the vehicle 1 is proactively recommended at which point he should best take over the driving task for carrying out the manual driving operation.

Claims (8)

Method for operating a vehicle (1), in which a steering wheel is positioned in a safety position when an automated driving operation is activated and in a steering position when a driving task is transferred from the vehicle (1) to a driver of the vehicle (1), characterized in that - in automated driving mode, a route (F) ahead of the vehicle (1) is analyzed with regard to the suitability of handing over the driving task, - the route (F) is analyzed in such a way that an amount of a maximum steering angle with respect to the route divided into segments (F) as well as a driving speed at which the vehicle (1) drives on the respective segment are predicted, and - based on the predicted steering angle and the predicted driving speed for each of the segments, a degree of suitability for handing over the driving task to the driver of the vehicle ( 1) is determined, - the determined different degrees of suitability for each segment of the route (F) are displayed to the driver of the vehicle (1) on a vehicle-side display unit. Procedure according to Claim 1 , characterized in that the different degrees of suitability are displayed in different colors on the display unit. Method according to one of the preceding claims, characterized in that the driver of the vehicle (1) requests the positioning of the steering wheel in the steering position by actuating an actuating element if he has the appropriate level of suitability and intends to take on the driving task. Method according to one of the preceding claims, characterized in that when the vehicle recognizes the need to hand over the driving task to the driver and the vehicle (1) is currently cornering, it is checked whether the handover will take place at a later point in time on a segment of the route (F). possible with a higher level of aptitude. Procedure according to Claim 4 , characterized in that when the driving task is handed over at a later point in time on the segment with a higher degree of suitability, the steering wheel is automatically positioned in the steering position at a later point in time. Procedure according to Claim 4 or 5 , characterized in that a countdown until the later point in time is reached and the driving task is handed over to the driver at this later point in time is optically output by means of a progress display (A) shown on the display unit. Method according to one of the preceding claims, characterized in that a suitability level suitable for handing over the driving task is displayed accordingly in color if the segment has a straight route and a wheel angle is 2° or less for a driving time of at least 3 seconds. Method according to one of the preceding claims, characterized in that a curve radius (r) of the route (F) divided into segments and traffic information applicable to the route (F) are continuously recorded.

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